Initialization code and entry point for Self Diagnostics Module

BASE/src/Microsoft.ApplicationInsights/Extensibility/Implementation/TelemetryConfigurationFactory.cs

@@ -57,6 +57,7 @@
             try
             {
                 SdkInternalOperationsMonitor.Enter();
+                SelfDiagnosticsModule.EnsureInitialized();
 
                 if (modules != null && !modules.Modules.Any(module => module is DiagnosticsTelemetryModule))
                 {

BASE/src/Microsoft.ApplicationInsights/Extensibility/Implementation/Tracing/SelfDiagnosticsModule.cs

@@ -0,0 +1,58 @@
+namespace Microsoft.ApplicationInsights.Extensibility.Implementation.Tracing
+{
+    using System;
+
+    /// <summary>
+    /// Self diagnostics class captures the EventSource events sent by Application Insights
+    /// modules and writes them to local file for internal troubleshooting.
+    /// </summary>
+    class SelfDiagnosticsModule : IDisposable
+    {
+        /// <summary>
+        /// Long-living object that hold relevant resources.
+        /// </summary>
+        private static readonly SelfDiagnosticsModule Instance = new SelfDiagnosticsModule();
+
+        // Long-living object that holds a refresher which checks whether the configuration file was updated
+        // every 10 seconds.
+        // private readonly SelfDiagnosticsConfigRefresher configRefresher;
+
+        static SelfDiagnosticsModule()
+        {
+            AppDomain.CurrentDomain.ProcessExit += (sender, eventArgs) =>
+            {
+                Instance.Dispose();
+            };
+        }
+
+        private SelfDiagnosticsModule()
+        {
+            // this.configRefresher = new SelfDiagnosticsConfigRefresher();
+        }
+
+        /// <summary>
+        /// Trigger CLR to initialize static fields and static constructors of SelfDiagnosticsModule.
+        /// No member of SelfDiagnosticsModule class is explicitly called when an EventSource class, say
+        /// AspNetCoreEventSource, is invoked to send an event.
+        /// This method needs to be called in order to capture any EventSource event.
+        /// </summary>
+        public static void EnsureInitialized()
+        {
+        }
+
+        /// <inheritdoc/>
+        public void Dispose()
+        {
+            this.Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                // this.configRefresher.Dispose();
+            }
+        }
+    }
+}